Pbocebs of pbodtjcdto impervious material



.5 sels containe'rs and other articles used laboratoriesand chemical plants orfactories, which is impervious to liquids or gases and .30 ficial graphite with '40 1 of-liquids or gases into theiyhoccupy. e

the filler, and

so vuntil the graphite is com letel the surface of the latter, the process of 68 imlpli'egnation is completed.

order to render the impregnated I mama M 15,1927. v

' UNITED "STATES PATIENT err-f es;

wnniaiim r. nan-noun; or nonnmin, cononnno.

raocns's or i nonucme mnavious Karenina.

ll'o Application filed December- This invention relates to the production of an impervious and chemical-resistant ma- .terial and its: principal object is to provide a material suitable for making conduits, veswhich is proof against the corrosive action of acids and other chemicals.

It is well known that artificial graphite while strictly chemical-proof, is by reason of its porosi not 'suitablefor use in therodnction o apparatus emplo ed to conuct oicontain chemical liqui or .gases,

and it-is another object of my invention to iicnlpregnate artificial'graphite with a chemr'esistan t substance so as to completely 1ts pores and becomega permanent and solid art thereof.

A rther object of the invention is to render articles composed entirely or in part of artificial graphite, impervious by fillin its pores or cells with a substance of hig internal cohesion, and still other objects reside in providing a sim le, economical and practic method of pro ucing material and articles of the above described character.

With the above and other objects in view, my invention consists in'impre ating artia preferab y chemicalresistant substance of high internal cohesion, which by filling the voids and pores of the graphite, becomes a permanent and solid part thereof. 7

at Particularly adapted for this purpose are naceous mabituminous or pyrogenous carbo terials such as asphalt, tar and pitch which are substantially inert at ordinary tern ratures and possess the degree of interna cohesion required to, prevent the penetration the cells or voids impregnation of the gra hits with these substances, maybe efiected by placing a it in a partial vacuum in a retort .or other closed container which is heated to a temperature slightly! above the melting point of I t en introducing the attcr in a melted conditiondnto the evacuated space inundated.

, be entered drawclean The filler may, if so, esire .into the retort under pressure and b3 ing its surplus 0d the grap ite an ters Patent is:

28,1921. Seria11o.525,489. -1

graphite resistant to all chemicals at any temperature, and im ervious toall solutions and ases, it is bake by any suitable method;

in a 'ln furnace or retort, care being taken to exclude oxygen and thereby prevent oxidation of the material. I

The baking ate in the process of produc ingthe material ardens and carbonizes the filler in'the res of the graphite and re- -moves the v0 atile constituents thereof, and it ma be repeated after re-impregnationof the o 'ect, as often asis necessa to comletely fill the voids of the graphite with a ard and solid substance.

It will beevident that to e dite the hardening and c'arbonization 'of t e hydrocarbonaceeus filler after impregnation of the graphite, it is ddsirable to use one having a large percentage of non-volatile base such as heavy asphalt, while to impregnate articles used only to carry or contain cold acids and the like, a light pitch such as that derived from the distillation of coal maybe employed with satisfactory results; Material made according to the invention is of particular advantage int-he manufacture of pipes and other conduits, tools, dishes, concentrating pans,

valves, pumps and other apparatus in which a high degree 'of resistance to chemical act on together with complete imperviousness is a desideratum.

. It will be p te y treated, as

understood that the artificial be impregnated and otherwise present I hereinabove described, before or after the article is formed and that while a carbonaceous substance of the character referred to, is referable, it ispossible within the spirit of the'invention to use a noncarbonaceous or inorganic, chemicall material to fill the pores of'the grap ite so as to render it chemically resistant and impervious to liquids or gases. I a The distinction which I make between inert pitch and asphalt is that pitchis a coal-tar 1. The process of producingmaterial of product. I

as a

the character described consisting in imum and completely filling and closing the pre ting a body of artificial graphite voids oi the artificial graphite,

witfi zsphalt, baking the impregnated body 3. The process of rendering a body of and repeating the impregnating and baking graphite impervious to liquids and gases l6 5 actions until the voids of the graphite are and consisting in immersing the body in filled. I liquefied asphalt under a partial vacuum,

2. The process of rendering a body of and completely fillinfiland closing the voids artificial graphite impervious to 11 uids and of the artificial grap 'te.

- consist ng in immersing the y in a In testimony whereof I have aflixed my 10 'quefied chemical-resistant substance of signature. r

high internal cohesion under a partial vacu- WARREN F. BLEECKER. 

